This relates generally to imaging systems and, more particularly, to imaging systems with back-side illuminated pixels.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Imager sensors (sometimes referred to as imagers) may be formed from a two-dimensional array of image sensing pixels. Each pixel includes a photosensitive element that receives incident photons (light) and converts the photons into electrical signals. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format. Some conventional image sensors may operate in a global shutter (GS) scanning mode. However, this may require having an additional charge storage node in the pixels of the image sensor, which consumes a significant portion of the available pixel area and increases the cost of the sensors. High dynamic range (HDR) global shutter pixels may be required to store a large amount of charge, further increasing the cost of the sensors.
It would therefore be desirable to be able to provide improved pixel designs for image sensors.